Use FirstName & LastName fields for registration.

[jonashendrickx]

Description

• Implements the First Name & Last Name fields added to the Users table.
• Upon extending the functionality, I discovered I implemented adding additional credentials incorrectly using the registration endpoint. We now properly use the POST /users/{userId}/credentials endpoint to add additional passkeys.

Shape

Screenshots

Checklist

I did the following to ensure that my changes were tested thoroughly:

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I did the following to ensure that my changes do not introduce security vulnerabilities:

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